The present invention is directed to an oral appliance for use in treatment of snoring and sleep apnea. More particularly, the present invention is directed to a pair of separate mouthpieces with ease of adjustability and which are designed to accommodate the differential in movement between the molars and incisors.
Typically, snoring is caused by the relaxation of the muscles in the upper throat relax. During breathing, inhalation and exhalation causes the soft tissues in the upper throat to vibrate creating the sound we identify as snoring. Sleep apnea results from a more pronounced obstruction of the upper air passage which results in a cessation of breathing. Severe cases of sleep apnea are life threatening should the individual fail to resume breathing. Lesser symptoms include excessive daytime drowsiness and increased blood pressure that can produce strokes and eventually, in extreme cases, cardiac arrest.
In some of these extreme cases, surgical correction is attempted to alleviate the symptoms of sleep apnea by a procedure such as a tracheotomy. Most patients would prefer a less extreme, non-invasive procedure such as an oral appliance. This has led to a proliferation of any number of mouthpiece type appliances designed to pull the mandible forward ensuring an adequate opening to permit sufficient ingress/egress of air to reduce or eliminate the problems associated with snoring and sleep apnea. Among those appliances which are adjustable to provide a variety of mandibular positions, most are difficult to adjust and require the intervention of a dentist. Further, none of the available devices takes into account the fact that the incisors typically open between 2 and 2½ times as far as the rear molars as the mandible pivots about its connection to the upper jaw. This results in ill-fitting appliances which fail to perform as well as they might. Some of the appliances do not permit lateral movement of one mouthpiece relative to the other. This can cause the jaw muscle to become aggravated, particularly for those patients who tend to grind their teeth during sleep.
The nocturnal oral airway dilator (NORAD) appliance of the present invention effectively deals with the problems of snoring and sleep apnea while overcoming the limitations of the prior art apparatus. The appliance of the present invention comprises a first mouthpiece element for engaging a wearer's teeth on an upper jaw, the first mouthpiece having an anterior portion and a pair of posterior portions; a second separate mouthpiece element for engaging a wearer's lower teeth on a mandible, the second mouthpiece having an anterior portion and a pair of posterior portions; a first pair of ramp surfaces, one on each of the posterior portions of the first mouthpiece element; a second pair of ramp surfaces, one on each of the posterior portions of the second mouthpiece element for engaging the first pair of ramp surfaces; whereby when the second mouthpiece element is adjusted so as to extend the wearer's mandible forward by an additional amount relative to the wearer's upper jaw, engagement between the first and second pair of ramp surfaces causes the mandible to be moved vertically away from the upper jaw by an additional amount.
A first plurality of lateral positional ribs are formed on the anterior portion of the first mouthpiece element and a second plurality of laterally extending positional ribs are formed on the anterior portion of the second mouthpiece element for engaging at least some of the first plurality of laterally extending ribs to adjustably position the second mouthpiece element longitdinally relative to the first mouthpiece element while permitting relative lateral movement between the first and second mouthpiece elements. Preferably, the first and second plurality of ribs each slope at identical angles, being ramped upwardly front to back at an angle greater than the slope on the first and second pairs of ramp surfaces. The ratio of the maximum height of the ribs to that of said first and second pairs of ramp surfaces are designed to mirror a opening differential between the wearer's front mouth opening and the wearer's rear mouth opening and most preferably has a value of between 2 and 2½.
The first and second mouthpiece elements are each made of two different bio-compatible, translucent plastic materials, a first plastic material with a Shore D hardness of about 30 and a softening point in the range between 120 and 180° F. and a second bio-compatible, translucent material having a Shore D hardness of at least 70 and which does not appreciably soften at temperatures below 200° F. The first plastic material is preferably ethylene vinyl acetate and the second plastic material is preferably an ethylene methyl acrylate co-polymer. The upper and lower mouthpieces will be color-coded so the wearer is clear about which is the upper and which is the lower mouthpiece.
Each pair of mouthpiece elements has a plurality of protrusions extending outwardly from each lateral portion. These protrusions are engageable by elastic bands which exert a force which simultaneously biases the lower mouthpiece element toward the upper mouthpiece element and exerts a forward bias on the lower mouthpiece element relative to the upper mouthpiece element.
Various other features, advantages, and characteristics of the present invention will become apparent after a reading of the following detailed description.